A millimeter-wave attenuation measurement standard from 26.5 GHz to 40 GHz

A millimeter-wave attenuation measurement standard using the audio frequency substitution method is described in this paper. Attenuation values up to 90 dB from 26.5 GHz to 40 GHz can be measured by this standard. An Inductive Voltage Divider is used as a reference voltage ratio standard at 5 kHz. A dual channel high-sensitivity receiver has been designed to make accurate measurement using a lock-in amplifier. The measurement uncertainty of the new standard is analyzed. The expanded measurement uncertainty of a 0 ~ 90 dB step attenuator at 40 GHz is estimated to be 0.0037 dB ~ 0.011 dB.